Digital: If you have an iPhone running iOS7 or above or iPad running iOS6 or above with the Lightning connector, you can use the Lightning to USB 3 Adapter from Apple, or the Lightning to USB Adapter from Apple, together with a powered hub to avoid the "this device draws too much power" error. You'll also need a USB cable. Links for these are below:

Digital: You can connect our DACs to many Android devices using a USB On The Go cable. Devices that shipped with Android M or N stock probably won't need additional player software, but earlier devices may need USB Audio Player Pro to play music. Some Android devices will need to be connected through a USB powered hub, since they cannot supply enough power to run the DAC.